A saw machine has safety devices to protect the operator from injury. For example, a riving knife may be fixedly mounted on the machine base behind the saw blade to prevent a phenomenon known as kickback, which occurs when the wood being cut is caught by the rear edge of the saw blade, lifted off the table, and propelled backwards toward the operator.
Such safety devices typically require adjustment. In particular, when changing out different sizes of saw blades for cutting different thickness of wooden materials, or when switching out different saw blades used for different working conditions, the height of the saw blade may have to be adjusted up and down. In such a case, the riving knife may also have to be adjusted subject to the adjusted position of the saw blade. Therefore, it is a desired function of a saw machine to allow quick mounting, dismounting and adjustment of the riving knife.
U.S. Pat. No. 6,840,144 B2 discloses a riving knife mounting structure, as reproduced in FIG. 1, which includes a control plate 1 having a sloping face 102, and which is movable to control a spring-loaded pin 2, causing the spring-loaded pin 2 to engage with a retaining hole 301 on a riving knife 3 or to move away from the retaining hole 301. Thus, the riving knife 3 can be vertically adjusted or detached from the machine for replacement.
Additionally, U.S. Pat. No. 7,437,981 B2, Taiwan Patent No. TW 1305160 and TW M280905 also disclose quick-detachable, quick-adjustable riving knife mounting structures.
The structure disclosed in U.S. Pat. No. 6,840,144 B2 (as shown in FIG. 1) allows for quick adjustment or replacement of the riving knife 3 on a mounting frame 4. However, when adjusting or replacing the riving knife 3, the operator must insert a hand into the inside of the machine base of the saw machine (not shown) to operate the control plate 1 within a narrow space. As such, it is inconvenient to operate this structure. U.S. Pat. No. 7,437,981 B2, Taiwan Patent No. TW 1305160 and TW M280905 also disclose structures that have the same problem.